1. Field of the Invention
This invention is related to apparatus for containing a leakage of polychlorinated biphenyl (PCB) compound and, in particular, to apparatus for containing a leakage of PCB compound from outdoor equipment while permitting rain water to be discharged into the outside environment. The invention relates especially to a float valve which allows water to flow while preventing the passage of PCB compounds.
2. Description of Prior Art
Most present day electrical transformers contain PCB compounds to facilitate the removal of heat generated in the transformers. Because the PCB is extremely hazardous to humans and does not break down in the environment, it is necessary to contain PCB spills so that the chemical does not reach the environment. When spills occur the cleanup is extremely expensive because all contaminated material must be collected and removed to a hazardous waste disposal site.
In the past, Imbiber valves were placed in the drain lines of electrical substation pads to contain any PCB which leaked from transformers or other electrical equipment. The Imbiber beads in the valves absorb the PCB (or other petroleum products) and expand to effectively block passage through the valve. However, water is able to pass through the Imbiber valve only at low flow rates even when no PCB is present and thus the valves severely restrict the passage of water from the electrical substation pads. During large rain storms, the restricted flow through the valves may cause water to back up into the electrical units resulting in damage to electrical switching equipment.